Skip to main content

The first generation Mazda MX-5, or Miata.

20 Questions View all

Why does my hazard fuze keep blowing?

The Miata is not my only car, so I haven't needed to tend to it. It looks like I have some downtime in the next week and figured I may as well address it. For a long while my third brake light was out. I went into the trunk, found a broken wire to the third brake light and hooked up the two ends to test. I connected the two halves of the wire more permanently and shortly after, I found my turn signals not working. I'm not positive those two things are related but they might be. I found a blown fuze to the hazard switch and replaced it. It solved the issue for about 3 minutes of driving before blowing again. Anybody know what might be wrong or where I should look to fix it?

Answer this question I have this problem too

Is this a good question?

Score 0
Add a comment

2 Answers

Question: Why does my hazard fuze keep blowing?

Answer: There is a short in the circuit somewhere. It could be a bad light bulb, a bulb socket, a wire rubbed through, a bad switch...something. Don't give up, you are bound to find it sooner or later.


Connect the bulb / circuit tester where the fuse connects, and then let the short hunting begin. When the light bulb goes out for the change made in the circuit, the short is then found. Make the repair, and retest. When the bulb stays out, the problem should be gone. If you want to stick with using the multi-meter, connect one lead to the fused side of the flasher circuit, and the other end to a good ground. Set the meter to read continuity...ohms. when the short is eliminated, the meter should show an open circuit. Either method should work.

Was this answer helpful?

Score 0
Add a comment


Here’s a composite image taken from the 1997 Mazda Miata service manual showing the wiring for the hazard lights and the high mount brake light (3rd brake light)

Check that the green wire from the high mount brake light only connects to the green wire that connects to the other brake lights and also the brake pedal switch. The other side of the brake lights should have a black wire connected to them. This is the earth wire.

The green wire comes from the switch on the brake pedal that extends power from the 15A stop fuse to operate all of the brake lights.

There is a green/black wire from the flasher unit that extends the power from the 15A hazard fuse to operate the left front and rear hazard lights and a green/white wire from the flasher unit to operate the right front and rear hazard lights.

Block Image

(click on image to enlarge)

Was this answer helpful?

Score 0
Add a comment

Add your answer

John Bradwell will be eternally grateful.
View Statistics:

Past 24 Hours: 4

Past 7 Days: 9

Past 30 Days: 29

All Time: 520